JP2948862B2 - Alkylphenylalkylpyrimidine compounds and compositions - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a liquid crystal compound useful in the fields of liquid crystal display devices and liquid crystal optical switching devices, and more particularly, it is suitable as a material for ferroelectric liquid crystal display devices. The present invention relates to a novel liquid crystal compound, in particular, a non-optically active liquid crystal compound responsible for a liquid crystal temperature range of a ferroelectric liquid crystal composition, a composition containing these compounds, and an element using the same.

[Background of the Invention and Prior Art]

Currently, TN (Twisted Nematic) is used as a liquid crystal display element.
The type display method is most widely used. This TN display has many advantages such as low driving voltage and low power consumption. However, the response speed is remarkably inferior to light-emitting display elements such as cathode ray tubes, electroluminescence, and plasma displays. 180 to 270 torsion angle
Although a new type of TN display element has been developed, the response speed is still inferior. Although various improvements have been made in this way, development of a TN display element having a high response speed has not yet been realized.

However, a remarkable improvement in response speed is expected in a new display method using ferroelectric liquid crystal, which has been actively studied at present (Clark et al .; Applied P.
hys.lett., 36 , 899 (1980)). This display method uses a chiral smectic phase such as a chiral smectic C phase (hereinafter, abbreviated as Sc * phase) exhibiting ferroelectricity. As for the liquid crystal phase exhibiting ferroelectricity, phases such as chiral smectic F, G, H, and I exhibit ferroelectricity in addition to the Sc * phase.

Many characteristics are required for ferroelectric liquid crystal materials used in ferroelectric liquid crystal display elements that are actually used. Ferroelectric liquid crystal compositions are provided in the form of a mixture. That is, the ferroelectric liquid crystal composition may be composed of only a ferroelectric liquid crystal compound, or may be a non-chiral smectic C / F / G / H / I or other inclined smectic phase (hereinafter referred to as Sc or the like). By a mixture of at least one ferroelectric liquid crystal compound or a non-liquid crystal optically active compound,
There is a method in which the whole is a composition exhibiting a ferroelectric liquid crystal phase.

As these basic substances, various kinds of compound groups exhibiting a non-chiral smectic liquid crystal phase such as Sc are used, but practically a liquid crystal compound exhibiting a smectic phase widely in a temperature range from low temperature to room temperature or higher. Alternatively, a liquid crystal composition is used. Among these smectic phases
Because the Sc phase exhibits the fastest response among the ferroelectric liquid crystal phases, it is generally and widely used as a basic substance liquid crystal phase. The components of these smectic C liquid crystal compositions include:
Phenylbenzoate, Schiff base, bifunyl,
Liquid crystal compounds such as phenylpyridine and phenylpyrimidine are exemplified.

Among them, 2- (4-alkoxyphenyl) -5-alkylpyrimidine is most frequently used as a basic substance of the ferroelectric liquid crystal composition. These are Fl
ssige Kristalle in Tabellen, page 260, and F
It is described in lssige Kristalle in Tabellen II, page 376, and there are many examples of using these.

2- (4-alkylphenyl) which is the compound of the present invention
The shorter alkyl chain length of -5-alkylpyrimidine is
Flssige Kristalle in Tabellen II, page 376 Is described.

 The phase transition temperatures are listed below.

n Cr S _A N I 5 ・ 10 ・ 26.5 ・ 6 ・ 29 ・ 7 ・ 15 ・ 29 ・ 8 ・ 18 ・ 29.5 ・ 9 ・ 23.5 ・ 30.5 ・ 33 ・ 10 ・ 31 (・ 29.3 ・ 31) ・ n increases , A nematic phase appears, and at first glance, even if the compound has an extended alkyl chain length,
It was thought that it was impossible to exhibit an inclined phase such as Sc, which is essential for the basic material of the ferroelectric liquid crystal.

in addition, There is no report that the compound actually shows a Sc phase, and there is no example in which the compound is used as a basic substance of a ferroelectric liquid crystal composition.

However, JP-A-63-22042 (page 7), JP-A-63-152347 (page 9), JP-A-63-201147 (page 8), JP-A-63-218647 (page 5), Prior documents such as JP-A-63-22147 (page 7) and JP-A-63-303951 (page 9) include: 2- (4-octyloxy-phenyl) -5-nonyl pyrimidine Cr · 33 ℃ Sc · 60 ℃ S A · 75 ℃ Iso (Cr: solid crystalline phase, Sc: smectic C phase, S _A: smectic A phase, Iso: Although it is described that (isotropic phase) is used as a component of the composition, this compound is a 2- (4-octylphenyl) -5-nonylpyrimidine produced by the present inventors. a _{S F · 24.6 ℃) S a} · 59.5 Iso (S F · smectic F phase) is different from that at all the phase transition temperature.

Meanwhile, Flssige Kristalle in Tabe
When Llen, page 261 2- (4-octyloxy-phenyl) -5-nonyl pyrimidine (compound No. 4162) reference, by almost coincides with Cr · 33 ℃ Sc · 60 ℃ S A · 75.5 ℃ Iso, the The compounds described in the prior art are completely different from the above-mentioned compounds produced by the present inventors, and it turns out that known compounds are erroneously written.

[Problems to be solved by the invention]

The response time of a display device using a ferroelectric liquid crystal composition is given by the following equation.

 τ∞η / Ps · E where τ is the response time η is the viscosity E is the electric field strength Ps is the spontaneous polarization value

Therefore, in order to reduce the response time in terms of materials,
There are two methods for increasing the spontaneous polarization value and reducing the viscosity.

Efforts have been made to increase Ps in known ferroelectric liquid crystal compositions, but no remarkable improvement in low viscosity is known.

The problem to be solved by the present invention is that the viscosity of the ferroelectric liquid crystal composition that is currently widely used is not sufficiently reduced, and the present invention reduces the viscosity by reducing the viscosity.
The purpose is to aim for a high-speed response of the element.

[Means for solving the problem]

The feature of the present invention is that a compound which has been considered impossible to be used as a basic substance of a ferroelectric liquid crystal composition until now has a tilted smectic phase which is essential as a component of the ferroelectric liquid crystal composition. It has been found that this compound has a very low viscosity as compared with conventionally known compounds and can be suitably used as a non-optically active basic component of the composition.

The present invention has the general formula (Wherein R ¹ is a straight-chain or branched alkyl group having 7 to 15 carbon atoms, and R ² is a straight-chain or branched alkyl group having 9 to 16 carbon atoms), And a smectic liquid crystal composition containing at least one such compound, or a ferroelectric liquid crystal composition comprising an optically active substance, more preferably an optically active liquid crystal, and still more preferably an optically active smectic liquid crystal. It is a ferroelectric liquid crystal device constituted by using a composition.

In the compounds of the above general formula, the number of carbon atoms of R ¹ is preferably 7 to 12, and a straight-chain compound is preferable. In the case of branching, an isopropyl structure or a sec-butyl structure is preferable. s
In the case of an ec-butyl structure, a racemic structure is preferable, and an optically active substance may be used.

Accordingly, preferred specific examples of R ¹ include heptyl, octyl, nonyl, decyl, undecyl, dodecyl, 5-methylhexyl, 6-methylheptyl, 7-methyloctyl, 8-methylnonyl, 9-methyldecyl, 10-methylundecyl , 4-methylhexyl, 5-methylheptyl, 6-methyloctyl, 7-methylnonyl, 8-methyldecyl, 9-methylundecyl, and the like.

Preferred number of carbon atoms in R ² is 10 to 12, but those of linear are preferred, isopropyl structures in the case of branched or sec-
A butyl structure is preferred. In the case of a sec-butyl structure, those having a racemic structure are preferable, and optically active substances may be used.

As preferred specific examples of R ² are therefore decyl, undecyl, dodecyl, 8- methylnonyl, 9- methyldecyl, 10-methyl undecyl, 7- methylnonyl, 8-methyldecyl, 9-methyl undecyl, and the like.

The basic substance of the ferroelectric liquid crystal composition is, in most cases,
Since it is composed only of non-optically active components, the chiral nematic phase, the chiral smectic phase, without being bothered by the pitch length and twist direction of each and the direction of Ps, etc., mainly, the liquid crystal temperature range, the refractive index anisotropy, What is necessary is just to design considering only dielectric anisotropy, viscosity, etc.

However, when either R ¹ or R ² has a sec-butyl structure and is an optically active substance, the chemical substance alone exhibits a ferroelectric liquid crystal phase. Therefore, in the case of non-optically active, no chiral nematic phase, chiral smectic phase,
Problems arise in adjusting the pitch length, twisting direction, direction of Ps, and the like.

In the case of the compound of the present invention, the optically active substance and the racemic form have almost the same phase transition temperature. Therefore, the racemic form which does not need to consider the above problem is preferable.

The compound of the present invention satisfies the essential condition of exhibiting a tilted smectic phase (specifically, C and F phases) which is a basic substance of a ferroelectric liquid crystal composition. Examples are given below including substances. Through No.
Compounds marked with ^* are compounds outside the scope of the present invention, and parentheses indicate phase transition temperatures.

2- (4-hexyl-phenyl) -5-hexyl pyrimidine ^(No.1) * 2- (4-hexyl-phenyl) -5-heptyl pyrimidine _{(Cr · 21.1 S A · 47.3} Iso) (No.2) * 2- (4-hexylphenyl) -5-octylpyrimidine (Cr 20.5 S _A 48.4 Iso) (No. 3) ^* 2- (4-hexylphenyl) -5-nonylpyrimidine (No. 4) ^* 2- (4 -Hexylphenyl) -5-decylpyrimidine (No. 5) ^* 2- (4-hexylphenyl) -5-undecylpyrimidine (No. 6) ^* 2- (4-hexylphenyl) -5-dodecylpyrimidine (No. .7) ^* 2- (4-hexylphenyl) -5-tridecylpyrimidine (No. 8) ^* 2- (4-hexylphenyl) -5-tetradecylpyrimidine (No. 9) ^* 2- (4-hexyl) Phenyl) -5-pentadecylpyrimidine (No .10) ^* 2- (4-hexylphenyl) -5-hexadecylpyrimidine (No. 11) ^* 2- (4-hexylphenyl) -5- (8-methylnonyl) pyrimidine (No. 12) ^* 2- ( 4-hexylphenyl) -5- (9-methyldecyl) pyrimidine (No. 13) ^* 2- (4-hexylphenyl) -5- (10-methylundecyl) pyrimidine (No. 14) ^* 2- (4- Hexylphenyl) -5- (7-methylnonyl) pyrimidine (No. 15) ^* 2- (4-hexylphenyl) -5- (8-methyldecyl) pyrimidine (No. 16) ^* 2- (4-hexylphenyl)- 5- (9-methyl-undecyl) pyrimidine ^(No.17) * 2-(4-heptyl-phenyl) -5- hexyl pyrimidine _{(Cr · 15.0 S A · 29.0} Iso) (No.18) * 2- (4- Heptylphenyl) -5-heptylpyrimi Down ^(No.19) * 2-(4-heptyl-phenyl) -5- octyl pyrimidine _{(Cr · 23.4 S A · 50.3} Iso) (No.20) * 2- (4- heptylphenyl) -5- nonyl pyrimidine ( _{Cr · 41.1 (S F · 24.0} ) S A · 59.7 Iso) (No.21) 2- (4- heptylphenyl) -5- decyl pyrimidine _{(Cr · 29.8 S F · 33.8} S C · 43.3 S A · 60.0 Iso ) (N
o.22) 2- (4-Heptylphenyl) -5-undecylpyrimidine (Cr 39.2 S _F 48.4 S _C 53.5 S _A 64.7 Is
o) (No.23) 2- (4-heptylphenyl) -5-dodecylpyrimidine (Cr 41.4 S _F 53.8 S _C 58.0 S _A 65.2 Iso)
(No.24) 2- (4-heptylphenyl) -5-tridodecylpyrimidine (No.25) 2- (4-heptylphenyl) -5-tetradecylpyrimidine (Cr 38.5 S _F 62.7 S _A 67.2 Iso) (No.2
6) 2- (4-heptylphenyl) -5-pentadecylpyrimidine (No. 27) 2- (4-heptylphenyl) -5-hexadecylpyrimidine (No. 28) 2- (4-heptylphenyl) -5 -(8-Methylnonyl) pyrimidine (No.29) 2- (4-heptylphenyl) -5- (9-methyldecyl) pyrimidine (No.30) 2- (4-heptylphenyl) -5- (10-methylun (Decyl) pyrimidine (No. 31) 2- (4-heptylphenyl) -5- (7-methylnonyl) pyrimidine (No. 32) 2- (4-heptylphenyl) -5- (8-methyldecyl) pyrimidine (No. 31) 33) 2- (4-heptylphenyl) -5- (9-methylundecyl) pyrimidine (No. 34) 2- (4-octylphenyl) -5-hexylpyrimidine (Cr 18.0 S _A 29.5 Iso) ( ^No.35) * 2- ( - octylphenyl) -5- heptyl pyrimidine _{(Cr · 18.5 S A · 48.1} Iso) (No.36) * 2- (4- octylphenyl) -5- octyl pyrimidine _{(Cr · 31.5 S A · 50.2} Iso) (No ^.37) * 2- (4-octylphenyl) -5- nonyl pyrimidine _{(Cr · 29.0 (S F ·} 24.6) S A · 59.8 Iso) (No.38) 2- (4- octylphenyl) -5- decyl Pyrimidine (Cr 33.6 S _F 36.7 S _C 46.2 S _A 59.8 Iso) (N
o.39) 2- (4-Octylphenyl) -5-undecylpyrimidine (Cr 41.0 S _F 50.8 S _C 55.4 S _A 64.2 Is
o) (No.40) 2- (4-octylphenyl) -5-dodecylpyrimidine (Cr ・ 47.5 S _F・ 55.6 S _C・ 62.2 S _A・ 64.2 Iso)
(No.41) 2- (4-octylphenyl) -5-tridecylpyrimidine (No.42) 2- (4-octylphenyl) -5-tetradecylpyrimidine (Cr / 57.7 S _F -64.5 S _C -66.3) Iso) (No.4
3) 2- (4-octylphenyl) -5-pentadecyl pyrimidine (No.44) 2- (4-octylphenyl) -5-hexadecyl pyrimidine _{(Cr · 56.0 S F · 67.0} Iso) (No.45) 2- (4-octylphenyl) -5- (8-methylnonyl) pyrimidine (No. 46) 2- (4-octylphenyl) -5- (9-methyldecyl) pyrimidine (No. 47) 2- (4-octyl) Phenyl) -5- (10-methylundecyl) pyrimidine (No. 48) 2- (4-octylphenyl) -5- (7-methylnonyl) pyrimidine (No. 49) 2- (4-octylphenyl) -5 -(8-methyldecyl) pyrimidine (No. 50) 2- (4-octylphenyl) -5- (9-methylundecyl) pyrimidine (No. 51) 2- (4-nonylphenyl) -5-hexylpyrimidine ( No.52) ^* 2- (4- Nonylphenyl) -5-heptyl pyrimidine ^(No.53) * 2- (4- nonylphenyl) -5-octyl pyrimidine _{(Cr · 27.3 S A · 51.2} Iso) (No.54) * 2- (4- nonylphenyl ) -5-Nonylpyrimidine (Cr 48.5 S _A 60.3 Iso) (No. 55) 2- (4-nonylphenyl) -5-decyl pyrimidine (Cr 32.5 S _F 36.5 S _C 44.0 S _A 60.7 Iso) (N
o.56) 2- (4-Nonylphenyl) -5-undecylpyrimidine (No.57) 2- (4-Nonylphenyl) -5-dodecylpyrimidine (Cr / 41.0 S _F / 56.8 S _C -63.2 S _A・ 65.6 Iso) (N
o.58) 2- (4-Nonylphenyl) -5-tridecylpyrimidine (No.59) 2- (4-Nonylphenyl) -5-tetradecylpyrimidine (No.60) 2- (4-Nonylphenyl) -5-pentadecylpyrimidine (No. 61) 2- (4-nonylphenyl) -5-hexadecylpyrimidine (No. 62) 2- (4-nonylphenyl) -5- (8-methylnonyl) pyrimidine (No. 61) 63) 2- (4-Nonylphenyl) -5- (9-methyldecyl) pyrimidine (Cr 40.0 (S _F 38.1) S _C 52.8 Is
o) (No. 64) 2- (4-nonylphenyl) -5- (10-methylundecyl) pyrimidine (No. 65) 2- (4-nonylphenyl) -5- (7-methylnonyl) pyrimidine (Cr・ 26.2 S _C・ 36.5 Iso) (No.66)
2- (4-nonylphenyl) -5- (8-methyldecyl) pyrimidine _{[Cr · 40.7 (S C · 37.9} ) Iso ] (No.67)
2- (4-nonylphenyl) -5- (9-methylundecyl) pyrimidine (No. 68) 2- (4-decylphenyl) -5-hexylpyrimidine (No. 69) ^* 2- (4-decylphenyl) ) -5- heptyl pyrimidine ^(No.70) * 2- (4- decylphenyl) -5- octyl pyrimidine _{(Cr · 35.5 S A · 49.7} Iso) (No.71) * 2- (4- decylphenyl) - 5-nonyl pyrimidine _{(Cr · 36.0 S A · 58.4} Iso) (No.72) 2- (4- -decyl) -5-decyl pyrimidine [Cr · 46.3 (Sc · 45.0) S A · 59.8 Iso ] (No. 73) 2- (4-decylphenyl) -5-undecylpyrimidine (Cr · 41.2 S _F · 52.6 S _C · 54.6 S _A · 64.6 Iso)
(No.74) 2- (4-decylphenyl) -5-dodecylpyrimidine (Cr 48.8 S _F 58.0 S _C 64.0 S _A 65.0 Iso) (N
o.75) 2- (4-decylphenyl) -5-tridecylpyrimidine (No.76) 2- (4-decylphenyl) -5-tetradecylpyrimidine (No.77) 2- (4-decylphenyl) -5-pentadecylpyrimidine (No. 78) 2- (4-decylphenyl) -5-hexadecylpyrimidine (No. 79) 2- (4-decylphenyl) -5- (8-methylnonyl) pyrimidine (No. 78) 80) 2- (4-decylphenyl) -5- (9-methyldecyl) pyrimidine (No. 81) 2- (4-decylphenyl) -5- (10-methylundecyl) pyrimidine (No. 82) 2- (4-decylphenyl) -5- (7-methylnonyl) pyrimidine (No. 83) 2- (4-decylphenyl) -5- (8-methyldecyl) pyrimidine (No. 84) 2- (4-decylphenyl) -5- (9-methylundecyl) Pyrimidine (No.85) 2- (4-Undecylphenyl) -5-hexylpyrimidine (No.86) ^* 2- (4-Undecylphenyl) -5-heptylpyrimidine (No.87) ^* 2- (4 -Undecylphenyl) -5-octylpyrimidine (No. 88) ^* 2- (4-undecylphenyl) -5-nonylpyrimidine (No.89) 2- (4-undecylphenyl) -5-decylpyrimidine ( No.90) 2- (4-Undecylphenyl) -5-undecylpyrimidine (No.91) 2- (4-Undecylphenyl) -5-dodecylpyrimidine (No.92) 2- (4-Undecyl) Phenyl) -5-tridecylpyrimidine (No. 93) 2- (4-undecylphenyl) -5-tetradecylpyrimidine (No. 94) 2- (4-undecylphenyl) -5-pentadecylpyrimidine (No. .95) 2- 4- (undecylphenyl) -5-hexadecylpyrimidine (No. 96) 2- (4-undecylphenyl) -5- (8-methylnonyl) pyrimidine (No. 97) 2- (4-undecylphenyl)- 5- (9-Methyldecyl) pyrimidine (No. 98) 2- (4-Undecylphenyl) -5- (10-methylundecyl) pyrimidine (No. 99) 2- (4-Undecylphenyl) -5 (7-methylnonyl) pyrimidine (No. 100) 2- (4-undecylphenyl) -5- (8-methyldecyl) pyrimidine (No. 101) 2- (4-undecylphenyl) -5- (9-methyl Undecyl) pyrimidine (No. 102) 2- (4-dodecylphenyl) -5-hexylpyrimidine (No. 103) ^* 2- (4-dodecylphenyl) -5-heptylpyrimidine (No. 104) ^* 2- ( 4-dodecylf Eniru) -5- octyl pyrimidine _{(Cr · 46.8 S A .48.3 Iso} ) (No.105) * 2- (4- dodecylphenyl) -5- nonyl pyrimidine _{(Cr · 44.1 S A · 57.8} Iso) (No.106 ) 2- (4-dodecylphenyl) -5- decyl pyrimidine _{(Cr · 50.1 S A 58.7 Iso} ) (No.107) 2- (4- dodecylphenyl) -5-undecyl pyrimidine [Cr · 52.9 (S _F · 52.2) S _A・ 63.6 Iso] (No.10
8) 2- (4-dodecylphenyl) -5-dodecylpyrimidine (Cr 59.5 S _F 59.7 S _C 64.0 S _A 64.7 Iso)
(No.109) 2- (4-dodecylphenyl) -5-tridecylpyrimidine (No.110) 2- (4-dodecylphenyl) -5-tetradecylpyrimidine (No.111) 2- (4-dodecylphenyl) ) -5-Pentadecylpyrimidine (No. 112) 2- (4-dodecylphenyl) -5-hexadecylpyrimidine (No. 113) 2- (4-dodecylphenyl) -5- (8-methylnonyl) pyrimidine (No. .114) 2- (4-Dodecylphenyl) -5- (9-methyldecyl) pyrimidine (No. 115) 2- (4-Dodecylphenyl) -5- (10-methylundecyl) pyrimidine (No. 116) 2 -(4-dodecylphenyl) -5- (7-methylnonyl) pyrimidine (No. 117) 2- (4-dodecylphenyl) -5- (8-methyldecyl) pyrimidine (No. 118) 2- (4-dodecylphenyl) ) 5- (9-methyl-undecyl) pyrimidine (No.119) 2-(4-tridecyl-phenyl) -5- hexyl pyrimidine ^(No.120) * 2-(4-tridecyl-phenyl) -5- heptyl pyrimidine ( No. 121) ^* 2- (4-tridecylphenyl) -5-octylpyrimidine (No. 122) ^* 2- (4-tridecylphenyl) -5-nonyllimidine (No. 123) 2- (4-tridecyl) Phenyl) -5-decylpyrimidine (No. 124) 2- (4-tridecylphenyl) -5-undecylpyrimidine (No. 125) 2- (4-tridecylphenyl) -5-dodecylpyrimidine (No. 126) ) 2- (4-Tridecylphenyl) -5-tridecylpyrimidine (No. 127) 2- (4-Tridecylphenyl) -5-tetradecylpyrimidine (No. 128) 2- (4-Tridecylphenyl) -5-pe Tadecylpyrimidine (No.129) 2- (4-tridecylphenyl) -5-hexadecylpyrimidine (No.130) 2- (4-Tridecylphenyl) -5- (8-methylnonyl) pyrimidine (No.131) ) 2- (4-Tridecylphenyl) -5- (9-methyldecyl) pyrimidine (No. 132) 2- (4-Tridecylphenyl) -5- (10-methylundecyl) pyrimidine (No.133) 2 -(4-Tridecylphenyl) -5- (7-methylnonyl) pyrimidine (No. 134) 2- (4-Tridecylphenyl) -5- (8-methyldecyl) pyrimidine (No. 135) 2- (4- Tridecylphenyl) -5- (9-methylundecyl) pyrimidine (No. 136) 2- (4-tetradecylphenyl) -5-hexylpyrimidine (No. 137) ^* 2- (4-tetradecylphenyl)- 5-hep Le pyrimidine ^(No.138) * 2- (4- tetradecylphenyl) -5- octyl pyrimidine ^(No.139) * 2- (4- tetradecylphenyl) -5- nonyl pyrimidine (No.140) 2-( 4-tetradecylphenyl) -5-decylpyrimidine (No. 141) 2- (4-tetradecylphenyl) -5-undecylpyrimidine (No142) 2- (4-tetradecylphenyl) -5-dodecylpyrimidine (No. .143) 2- (4-tetradecylphenyl) -5-tridecylpyrimidine (No. 144) 2- (4-tetradecylphenyl) -5-tetradecylpyrimidine (No. 145) 2- (4-tetradecyl) Phenyl) -5-pentadecylpyrimidine (No. 146) 2- (4-tetradecylphenyl) -5-hexadecylpyrimidine (No. 147) 2- (4-tetradecylphenyl) -5- ( 8-Methylnonyl) pyrimidine (No. 148) 2- (4-tetradecylphenyl) -5- (9-methyldecyl) pyrimidine (No149) 2- (4-tetradecylphenyl) -5- (10-methylundecyl) Pyrimidine (No. 150) 2- (4-tetradecylphenyl) -5- (7-methylnonyl) pyrimidine (No. 151) 2- (4-Tetradecylphenyl) -5- (8-methyldecyl) pyrimidine (No. 152) 2- (4-tetradecylphenyl) -5- (9-methylundecyl) pyrimidine (No. 153) 2- (4-pentadecylphenyl) -5-hexylpyrimidine (No. 154) ^* 2- ( 4-Pentadecylphenyl) -5-heptylpyrimidine (No. 155) ^* 2- (4-hetadecylphenyl) -5-octylpyrimidine (No. 156) ^* 2- (4-pentadecylphenyl)- 5-nonylpyrimidine (No. 157) 2- (4-pentadecylphenyl) -5-decylpyrimidine (No. 158) 2- (4-pentadecylphenyl) -5-undecylpyrimidine (No. 159) 2- (4-pentadecylphenyl) -5-dodecylpyrimidine (No. 160) 2- (4-pentadecylphenyl) -5-tridecylpyrimidine (No. 161) 2- (4-pentadecylphenyl) -5-tetra Decylpyrimidine (No. 162) 2- (4-pentadecylphenyl) -5-pentadecylpyrimidine (No. 163) 2- (4-pentadecylphenyl) -5-hexadecylpyrimidine (No. 164) 2- ( 4-pentadecylphenyl) -5- (8-methylnonyl) pyrimidine (No. 165) 2- (4-pentadecylphenyl) -5- (9-methyldecyl) pyrimidine (No. 166) 2- (4- Untadecylphenyl) -5- (10-methylundecyl) pyrimidine (No.167) 2- (4-pentadecylphenyl) -5- (7-methylnonyl) pyrimidine (No.168) 2- (4-pentadecyl) Phenyl) -5- (8-methyldecyl) pyrimidine (No. 169) 2- (4-pentadecylphenyl) -5- (9-methylundecyl) pyrimidine (No. 170) 2- (4- (6-methyl) (Heptyl) phenyl) -5-hexylpyrimidine (No.171) 2- (4- (6-methylheptyl) phenyl) -5-heptylpyrimidine (No.172) 2- (4- (6-methylheptyl) phenyl) -5-octylpyrimidine (No.173) 2- (4- (6-methylheptyl) phenyl) -5-nonylpyrimidine (No.174) 2- (4- (6-methylheptyl) phenyl) -5-decylpyrimidi (No. 175) 2- (4- (6-methylheptyl) phenyl) -5-undecylpyrimidine (No. 176) 2- (4- (6-methylheptyl) phenyl) -5-dodecylpyrimidine (No. .177) 2- (4- (6-methylheptyl) phenyl) -5-tridecylpyrimidine (No. 178) 2- (4- (6-methylheptyl) phenyl) -5-tetradecylpyrimidine (No. 179) ) 2- (4- (7-methyloctyl) phenyl) -5-hexylpyrimidine (No. 180) ^* 2- (4- (7-methyloctyl) phenyl) -5-heptylpyrimidine (No. 181) ^* 2 -(4- (7-methyloctyl) phenyl) -5-octylpyrimidine (No. 182) ^* 2- (4- (7-methyloctyl) phenyl) -5-nonylpyrimidine (Cr 29.5 S _F 31.0 S _A・ 58.2 Is
o) (No. 183) 2- (4- (7-methyloctyl) phenyl) -5-decylpyrimidine (Cr 38.6 S _F 41.3 S _C 51.4 S _A
58.4 Iso) (No. 184) 2- (4- (7-methyloctyl) phenyl) -5-undecylpyrimidine (No. 185) 2- (4- (7-methyloctylphenyl) -5-dodecylpyrimidine ( No.186) 2- (4- (7-methyloctyl) phenyl) -5-tridecylpyrimidine (No.187) 2- (4- (7-methyloctyl) phenyl) -5-tetradecylpyrimidine (No. 188) 2- (4- (8-methylnonyl) phenyl) -5-hexylpyrimidine (No. 189) ^* 2- (4- (8-methylnonyl) phenyl) -5-heptylpyrimidine (No. 190) ^* 2- (4- (8-methylnonyl) phenyl) -5-octylpyrimidine (No. 191) ^* 2- (4- (8-methylnonyl) phenyl) -5-nonylpyrimidine (No. 192) 2- (4- (8 -Methylnonyl) phenyl)- -Decylpyrimidine (No. 193) 2- (4- (8-methylnonyl) phenyl) -5-undecylpyrimidine (No. 194) 2- (4- (8-methylnonyl) phenyl) -5-dodecylpyrimidine (No. .195) 2- (4- (8-methylnonyl) phenyl) -5-tridecylpyrimidine (No. 196) 2- (4- (8-methylnonyl) phenyl) -5-tetradecylpyrimidine (No. 197) 2 -(4- (9-methyldecyl) phenyl) -5-hexylpyrimidine (No. 198) ^* 2- (4- (9-methyldecyl) phenyl) -5-heptylpyrimidine (No. 199) ^* 2- (4- (9-methyldecyl) phenyl) -5-octylpyrimidine (No. 200) ^* 2- (4- (9-methyldecyl) phenyl) -5-nonylpyrimidine (No. 201) 2- (4- (9-methyldecyl) Phenyl ) -5-Decylpyrimidine (No. 202) 2- (4- (9-methyldecyl) phenyl) -5-undecylpyrimidine (No. 203) 2- (4- (9-methyldecyl) phenyl) -5-dodecyl Pyrimidine (No. 204) 2- (4- (9-methyldecyl) phenyl) -5-tridecylpyrimidine (No. 205) 2- (4- (9-methyldecyl) phenyl) -5-tetradecylpyrimidine (No. 206) 2- (4- (10-Methylundecyl) phenyl) -5-
Hexylpyrimidine (No.207) ^* 2- (4- (10-methylundecyl) phenyl) -5-
Heptylpyrimidine (No.208) ^* 2- (4- (10-methylundecyl) phenyl) -5-
Octylpyrimidine (No.209) ^* 2- (4- (10-methylundecyl) phenyl) -5-
Nonylpyrimidine (No. 210) 2- (4- (10-methylundecyl) phenyl) -5
Decyl pyridimine (No. 211) 2- (4- (10-methylundecyl) phenyl) -5
Undecyl pyrimidine (No. 212) 2- (4- (10-methylundecyl) phenyl) -5-
Dodecyl pyrimidine (No. 213) 2- (4- (10-methylundecyl) phenyl) -5
Tridecyl pyrimidine (No. 214) 2- (4- (10-methylundecyl) phenyl) -5-
Tetradecylpyrimidine (No.215) 2- (4- (6-methyloctyl) phenyl) -5-hexylpyrimidine (No.216) ^* 2- (4- (6-methyloctyl) phenyl) -5-heptylpyrimidine (No.217) ^* 2- (4- (6-methyloctyl) phenyl) -5-octylpyrimidine (No.218) ^* 2- (4- (6-methyloctyl) phenyl) -5-nonylpyrimidine (No. .219) 2- (4- (6-Methyloctyl) phenyl) -5-decylpyrimidine (No. 220) 2- (4- (6-Methyloctyl) phenyl) -5-undecylpyrimidine (No. 221) 2- (4- (6-methyloctyl) phenyl) -5-dodecylpyrimidine (No. 222) 2- (4- (6-methyloctyl) phenyl) -5-tridecylpyrimidine (No. 223) 2- ( 4- (6-methylo Chill) phenyl) -5-tetradecyl pyrimidine (No.224) 2- (4- (7- methylnonyl) phenyl) -5- hexyl pyrimidine ^{(No.225) * 2- (4- (} 7- methylnonyl) phenyl) 5- heptyl pyrimidine ^{(No.226) * 2- (4- (} 7- methylnonyl) phenyl) -5- octyl pyrimidine ^{(No.227) * 2- (4- (} 7- methylnonyl) phenyl) -5-nonyl Pyrimidine (No.228) 2- (4- (7-methylnonyl) phenyl) -5-decylpyrimidine (No.229) 2- (4- (7-methylnonyl) phenyl) -5-undecylpyrimidine (No.230) ) 2- (4- (7-methylnonyl) phenyl) -5-dodecylpyrimidine (No. 231) 2- (4- (7-methylnonyl) phenyl) -5-tridecylpyrimidine (No. 232) 2- (4 -(7- Chirunoniru) phenyl) -5-tetradecyl pyrimidine (No.233) 2- (4- (8- methyldecyl) phenyl) -5- hexyl pyrimidine ^{(No.234) * 2- (4- (} 8- methyldecyl) phenyl) 5- heptyl pyrimidine ^{(No.235) * 2- (4- (} 8- methyldecyl) phenyl) -5- octyl pyrimidine ^{(No.236) * 2- (4- (} 8- methyldecyl) phenyl) -5-nonyl Pyrimidine (No.237) 2- (4- (8-methyldecyl) phenyl) -5-decylpyrimidine (No.238) 2- (4- (8-methyldecyl) phenyl) -5-undecylpyrimidine (No.239) ) 2- (4- (8-methyldecyl) phenyl) -5-dodecylpyrimidine (No. 240) 2- (4- (8-methyldecyl) phenyl) -5-tridecylpyrimidine (No. 241) 2- (4 − ( 8-methyldecyl) phenyl) -5-tetradecylpyrimidine (No. 242) 2- (4- (9-methylundecyl) phenyl) -5
Hexylpyrimidine (No.243) ^* 2- (4- (9-methylundecyl) phenyl) -5-
Heptylpyrimidine (No.244) ^* 2- (4- (9-methylundecyl) phenyl) -5-
Octylpyrimidine (No. 245) ^* 2- (4- (9-methylundecyl) phenyl) -5-
Nonylpyrimidine (No. 246) 2- (4- (9-methylundecyl) phenyl) -5
Decylpyrimidine (No.247) 2- (4- (9-methylundecyl) phenyl) -5-
Undecylpyrimidine (No.248) 2- (4- (9-methylundecyl) phenyl) -5-
Dodecyl pyrimidine (No. 249) 2- (4- (9-methylundecyl) phenyl) -5
Tridecylpyrimidine (No. 250) 2- (4- (9-methylundecyl) phenyl) -5
Compound of claims tetradecyl pyrimidine (No.251) This application is specifically as described above has a only compounds exhibiting S _C phase or S _F phase, here is a novelty of the invention.

R ² plays a major role in determining whether the compound of the present invention exhibits a tilted smectic phase. In the compound having 8 or less carbon atoms of R ² , the smectic phase that appears is S _A
Phase. This is the same as the previous knowledge,
It cannot be used as a basic substance of a ferroelectric liquid crystal composition.
In contrast, in the number of carbon atoms in R ² is 9 or more compounds, a ferroelectric liquid crystal composition smectic phase is tilted can be used as basic material, in this case appears the S _C phase and S _F phase. In this case, the appearing liquid crystal temperature range is not significantly affected by the carbon number of R ¹ .

In order to clarify this relationship, changes in the phase transition temperature when R ¹ and R ² are fixed are shown in FIGS. 1A to 1D.

FIG. 1A shows the carbon number of R ¹ is 7, FIG. 1B shows the carbon number of R ¹ is 8, FIG. 1C shows the carbon number of R ¹ is 9, and FIG. 1D shows the carbon number of R ¹ In the case of 10, R ₂
Shows the change in the phase transition temperature when the alkyl chain length of each is changed.

When either R ¹ or R ² has a branched structure, the liquid crystal temperature range exhibiting a tilted smectic phase indispensable for the basic substance is slightly lower than that of the corresponding compound having a linear structure. Moreover, hardly exhibit S _A phase, there is a tendency that the temperature range to S _F phase is moving.

When this branched compound is used as a ferroelectric liquid crystal composition, the tilt angle is larger than that of a linear compound. This means that it is very useful as a material for adjusting the tilt angle, which is one of the properties of the ferroelectric liquid crystal.

The invention described in claim (2) below is a composition and a device containing the compound of the above general formula. In the case of the composition, unlike the compound, even a compound that does not show a tilted smectic phase by itself can be used within a range that does not significantly impair the temperature range of the composition.

The smectic liquid crystal composition of claim (2) is used as a part constituting a basic substance of a ferroelectric liquid crystal composition.
It is impossible to form a ferroelectric liquid crystal element using only the non-optically active liquid crystal composition. However, the superiority of the basic substance is a major factor that determines most of the liquid crystal physical properties of the ferroelectric liquid crystal composition regardless of the superiority of the added optically active substance.

Among the physical properties of the liquid crystal, physical properties such as the temperature range of the ferroelectric liquid crystal, viscosity, elastic constant, refractive index anisotropy, dielectric anisotropy, and inclination angle almost reflect the physical properties of the basic substance. Therefore, it can be said that adjusting a non-optically active smectic liquid crystal composition having good performance is the basis for forming a ferroelectric liquid crystal composition having good performance. Therefore, claim (2)
The liquid crystal compositions described are sufficiently significant.

In the case of forming a non-optically active smectic liquid crystal composition, the following two methods can be considered.

(1) It comprises the compound of the present invention alone or a plurality of compounds of the present invention alone.

(2) It comprises one or more compounds of the present invention and one or more compounds other than the present invention.

As the compound other than the present invention in the case of (3), a smectic liquid crystal compound, particularly a compound exhibiting an inclined smectic liquid crystal phase is most suitable. Examples of the compound exhibiting the tilted smectic liquid crystal phase include the following compounds.

(Where R and R ′ are the same or different alkyl groups,
X and X 'represent the same or different alkyl groups or alkoxy groups. Many of the compounds of the present invention exhibit a smectic liquid crystal phase relatively inclined to a portion close to room temperature. Therefore, compounds other than the present invention to be combined are those exhibiting a smectic liquid crystal phase slightly inclined from room temperature to a high temperature side. Is preferred.

The ferroelectric liquid crystal composition is formed by appropriately adding one or more kinds of optically active substances or compounds to the thus formed non-optically active smectic liquid crystal composition as a basic substance. can do. (Claim 3).

It is desired that the optically active compound to be added exhibits a liquid crystal state, more preferably a ferroelectric liquid crystal state. This is because mixing a non-liquid crystal substance with a non-optically active tilted smectic liquid crystal composition that is responsible for the ferroelectric liquid crystal temperature range significantly lowers the ferroelectric liquid crystal temperature range, and in the worst case, the liquid crystal temperature This is because there is a possibility that the range may be lost. In this regard, when the compound to be added exhibits a ferroelectric liquid crystal phase, such a phenomenon rarely occurs, and the physical properties of the basic substance are hardly deteriorated. Even if the substance to be added is a non-liquid crystal substance, as long as the molecular structure is similar to the liquid crystal substance, the physical properties of the basic substance are hardly deteriorated.

In view of the above, the following optically active compounds can be added to the non-optically active smectic liquid crystal composition containing the compound of the present invention as a basic substance.

[Effects of the Invention] As described above, the first feature of the present invention is that 2- (4-alkylphenyl) which has been considered to be impossible to use as a basic substance of a ferroelectric liquid crystal composition. ) In the 5-alkylpyrimidine compound, an inclined smectic phase such as an SC or SF phase which is essential as a component of the ferroelectric liquid crystal composition is found, and these compounds are suitably used as a non-optically active basic component of the composition. The second characteristic feature is that these compounds have a very low viscosity as compared with conventionally known compounds, and as a result, a ferroelectric liquid crystal element capable of very high-speed response can be obtained. It can be configured.

As can be seen by comparing Example 2 and Reference Example 1 in Examples described later, the liquid crystal temperature range as the basic substance of the compound of the present invention is equal to or less than that of the compound used in Reference Example 1. The compounds of the invention are somewhat inferior. Also in the comparative example in which the optically active compound in Example 3 was added, the composition 3 using the compound of the present invention had a lower upper limit of the ferroelectric liquid crystal temperature range, and the ferroelectric liquid crystal temperature range was known. It is inferior to something. However, the low viscosity of the liquid crystal is often due to the reversal of the inferior temperature range, as described below.

As shown in Example 4, composition 3, which is the composition of the present invention, has a Ps of about 1/3 smaller than that of reference composition 4, but has a viscosity of about 1/10, The value of η ₀ taking the tilt angle into account is also about 1/2. As a result, a surprisingly fast response of 1/5 response time is achieved compared to composition 4.

In order to clarify the superiority of the compound of the present invention, the temperature dependence of the response time τ of composition 3 and composition 4 is shown in FIG. As is clear from the figure, it is understood that the compound of the present invention is extremely excellent as a basic substance having a fast response. This is due to the low viscosity of the compounds of the present invention.

(Method for producing compound)

The compound of the present invention can be suitably produced by the following route.

That is, 4-alkylbenzamidine hydrochloride (1)
And an alkyl malonic acid diester (2) in the presence of a base such as sodium hydroxide, potassium hydroxide or sodium alkoxide, an alcoholic solvent such as methanol or ethanol, an aprotic compound such as THF, ether, DMF or acetone. The 3,5-dihydroxypyrimidine compound (3) can be obtained by reacting with a non-ionic solvent or the like as a solvent at a temperature ranging from room temperature to the boiling point of the solvent.

3,5-Dihalogenpyrimidine compound (4), wherein (3) is chlorinated with a chlorinating reagent such as phosphorus oxychloride, phosphorus trichloride, phosphorus pentachloride or the like and, in some cases, replaced with halogen such as bromine or iodine. And

(4) with a dehalogenation catalyst such as Pd / c, Ra-Ni,
The desired product (I) can be obtained by dehalogenation.

Further, the production can be suitably performed by the following route.

That is, 4-alkylbenzamidine hydrochloride (1)
And α-alkyl-β-ethoxy-acrolein (5)
Is reacted in the presence of a base such as sodium hydroxide or sodium alkoxide in a solvent such as ethanol or methanol to produce the objective (I).

Further, the following compounds can be used in place of compound (5).

These compounds are all available from the 43rd Synthetic Organic Chemistry Society of Japan.
Vol. 10 (1985), p. 951.

Compound (1) can be produced by the following known method.

That is, dry hydrogen chloride is allowed to act on 4-alkylbenzonitrile (11) in the presence of methanol to produce imide ether hydrochloride, which is further reacted with ammonia to give 4-alkylbenzamidine hydrochloride (1). Can be manufactured.

Compound (2) can be suitably produced by the following method.

(Where Y is a halogen atom such as chlorine, bromine or iodine,
p- toluenesulfonyloxy group, benzenesulfonyloxy group, methanesulfonyloxy group, a leaving group such as trifluoromethane sulfonyloxy group) That is, an alkylating agent R ² -Y (13) with sodium ethoxide, hydroxide By reacting the malonic acid diester (14) in a solvent such as acetone or ethanol in the presence of a base such as sodium or potassium carbonate, the alkyl malonic acid diester (2) can be suitably produced.

〔Example〕

Hereinafter, the compounds and compositions of the present invention will be described in more detail with reference to Examples.

 Various methods for measuring the properties of the ferroelectric liquid crystal were based on the following.

(1) Spontaneous polarization (Ps) was measured by the triangular wave method.

(2) The tilt angle (θ) is the extinction position when a sufficiently high electric field equal to or higher than the critical electric field is applied to the homogeneously aligned cell;
It was obtained as 1/2 of the movement angle of the extinction position during polarity reversal.

(3) Response time (τ) is obtained by applying a composition to a 10 μm-thick cell with a transparent electrode that has been coated with polyvinyl alcohol as an alignment treatment agent, rubbed on the surface and subjected to parallel alignment treatment, and then ± 10 V / μm. , And a change time of the transmitted light intensity when a rectangular wave of 100 Hz was applied.

(4) The viscosity (η) was obtained by calculating from the half width of the peak of the polarization reversal current curve during the measurement of the triangular wave and the spontaneous polarization (H. Take
zoe et al, Japan Journal of Applied Physics (Jpn.J. Appl. Phys.), 26, L25
5 (1987)).

Further, since Ps and η largely depend on θ, in order to make the measured value independent of θ, Ps is sin
For θ, η was set to P ₀ and η ₀ respectively normalized by sin ² θ.

In Example 1 2- (4-decyl-phenyl) -5- dodecyl pyrimidine ((I) _{^{formula, R 1 = n-C 10}} H 21, R 2 = n-C 12 H 25
10 g of 4-decylbenzamidine hydrochloride (manufactured from 4-decylbenzanitrile (bp 152 ° C./3 mmHg)) and diethyl dodecylmalonate (manufactured from diethyl malonate and dodecylpromide (bp 155 ° C./2 mmHg) 6) A mixture of 12.2 g, 3.7 g of sodium methoxide and 200 ml of methanol
The mixture was stirred and refluxed for an hour. The reaction mixture was poured into 500 ml of 20% acetic acid, and the resulting solid was collected by filtration to give 2- (4-decylphenyl) -4,6-dihydroxy-5-dodecylpyrimidine.
6 g were obtained.

A mixture of the whole amount, 5 g of N, N-dimethylaniline and 100 g of phosphorus oxychloride was stirred and heated under reflux for 20 hours. Excess phosphorus oxychloride was distilled off under reduced pressure, the residue was poured into water, extracted with 300 ml of toluene, and the organic layer was washed with acid, washed with alkali, washed with water, dried, and concentrated. The residue was purified by column chromatography packed with activated alumina using toluene as an eluent, the effluent was concentrated, recrystallized using ethanol, and 2- (4-decylphenyl) -4,6-
Dichloro-5-dodecylpyrimidine (melting point: 56.3-56.8
C) 9.1 g.

The total amount of this 5% Pd / C 0.5g, triethylamine
A mixture of 5.2 g, 100 ml of heptane and 300 ml of ethanol was subjected to a hydrogenolysis reaction in a hydrogen atmosphere. After the reaction,
Pd / c was separated by filtration, 250 ml of toluene was added to the filtrate, and the resultant was pickled.
After washing with alkali, washing with water, drying, and concentration. The residue was recrystallized from alcohol to give the title 2- (4-decylphenyl) -5-dodecylpyrimidine (7.0 g).

 The phase transition temperature of this compound was as follows.

Cr · 48.8 SF · 58.0 Sc · 64.0 S _A 65.0 Iso Thus, the compound of the present invention exhibited a smectic phase inclined in a wide range.

Example 2 (Use Example 1) An equal mixture (composition 1) of the following compounds, which are the compounds of the present invention, was prepared.

Composition 1 was a non-optically active smectic liquid crystal composition, and its phase transition temperature was as follows.

Cryst-SF.53.0 SC.59 SA.65 Iso As described above, a smectic phase inclined in a wide range from room temperature was exhibited.

Reference Example 1 An equal mixture (composition 2) of the following known compounds was prepared.

The phase transition temperature of Composition 2 was as follows.

Cryst-SC • 59 SA • 66 N • 69 Iso Example 3 (Use Example 2) The following compound was added to Composition 1 prepared in Use Example 1 to prepare a ferroelectric liquid crystal composition 3.

Composition 1 80% by weight Compound 1 20% by weight Composition 3 is an optically active smectic liquid crystal composition and also a ferroelectric liquid crystal composition. The phase transition temperature was as follows.

Cryst〜SC ・ 37.5 SA ・ 61 Iso As described above, a ferroelectric liquid crystal phase was exhibited in a wide range from room temperature.

The chemical structure and phase transition temperature of Compound 1 are as follows.

Reference Example 2 Ferroelectric liquid crystal composition 4 was prepared by adding the following compounds to Composition 2 prepared in Reference Example 1.

Composition 2 80% by weight Compound 1 20% by weight Composition 4 is an optically active smectic liquid crystal composition and also a ferroelectric liquid crystal composition. The phase transition temperature was as follows.

Cryst to SC · 54.8 N ^* · 68.3 Iso Example 4 (Measurement Example) The liquid crystal properties of the ferroelectric liquid crystal compositions of Use Example 2 and Reference Example 2 were measured. The measurement temperature is 25 ° C.

 In addition, each unit of the physical property value is as follows.

Spontaneous polarization (Ps) nC / cm ² Tilt angle (θ) degree Response time (τ) μs Viscosity (η) Centipoise P ₀ Ps / sin θ η ₀ η / sin ² θ Sample Ps θ τ η P ₀ η ₀ Composition 3 14.4 12.0 9 6 70 139 Composition 4 58.6 30.5 43 72 104 288 From these results, the characteristics of the composition of the present invention become clear.

That is, although the composition 3 contains the same optically active compound by the same weight as the composition 4,
Ps appears small and the tilt angle also becomes small. The small Ps has a direction opposite to the high-speed response of the element, but the viscosity η is extremely small, and as a result, the response speed is significantly shortened.

Example 5 Compound of the Invention And the following compound exhibiting the Sc phase (Composition 5) was prepared. Composition 5 is not a ferroelectric liquid crystal composition because it is composed of a non-optically active compound.

 The phase transition temperature of Composition 5 was as follows.

_{Cr- · 0 Sc · 44 S A} · 104 N · 109 Iso could configure a smectic liquid crystal composition exhibiting a Sc phase in a wide range in this manner including room temperature.

Example 6 Using the composition 5 prepared in the example 5, the following composition 6 was constituted.

Composition 5 80% by weight Compound 1 20% by weight Composition 6 is an optically active smectic liquid crystal and a ferroelectric liquid crystal. The phase transition temperature of this composition was as follows.

Cr− to Sc ^* · 69 S _A · 90 N ^* · 103 Iso As described above, the ferroelectric liquid crystal phase was exhibited in a wide temperature range including room temperature.

The liquid crystal properties of this composition at 25 ° C. were as follows.

Sample Ps θ τ η P ₀ η ₀ Composition 6 42.2 21.5 24 35 117 267 As described above, the ferroelectric liquid crystal composition of the very high speed response is obtained.

Example 7 Composition 5 in Example 5 Instead of having a branched structure Was used to prepare Composition 7.

Composition 7 is a non-optically active smectic liquid crystal composition. The phase transition temperature of Composition 7 was as follows.

Cr · 1 S _F · 21 Sc · 78 S _A · 98 N · 103 Iso Thus, a composition exhibiting a smectic liquid crystal phase could be formed over a wide range including room temperature.

In composition 7, an SF phase appears on the lower temperature side as compared with composition 5. Since it is not preferable that the order of the liquid crystal phase changes within the driving temperature range, it can be said that the composition 5 is inferior to the liquid crystal temperature range.

Example 8 Using the composition 7 prepared in the example 7, the following composition 8 was constituted.

Composition 7 80% by weight Compound 1 20% by weight Composition 8 was a ferroelectric liquid crystal, and its phase transition temperature was as follows.

_{^{Cr~Sc * · 75 S A · 80}} N * · 99 Iso thus exhibited a ferroelectric liquid crystal phase in a wide range including room temperature.

The liquid crystal properties of this composition 8 at 25 ° C. were as follows.

Sample Ps θ τ η P ₀ η ₀ Composition 8 61.0 29.5 37 67 124 297 As described above, a ferroelectric liquid crystal composition having a very fast response was obtained.

Composition 8 has a tilt angle as large as nearly 10 ° as compared to composition 6. At present, the tilt angle is preferably 22.5 ° for the ferroelectric liquid crystal display system, that is, 22.5 ° for the birefringent type, and 45 ° for the guest-host type. The compound of the present invention having a branched structure can be effectively used as a material for adjusting a tilt angle.

〔The invention's effect〕

According to the present invention, it is possible to provide a liquid crystal compound that exhibits a tilted smectic phase as a basic substance of a ferroelectric liquid crystal composition, has low viscosity, and exhibits high-speed response when used as a liquid crystal display device.

[Brief description of the drawings]

FIG. 1A, FIG. 1B, FIG. 1C, and FIG. 1D are diagrams each showing a relationship between an alkyl chain length and a phase transition temperature. FIG. 2 is a diagram showing the temperature dependence of the response time of the composition according to the present invention.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-12476 (JP, A) JP-A-2-206681 (JP, A) JP-A-2-275864 (JP, A) JP-A-63-1988 22042 (JP, A) JP-A-61-251672 (JP, A) International publication 86/87 (WO, A1) European publication 356672 (EP, A1) (58) Fields investigated (Int. Cl. ⁶ , DB name) ) C07D 239/26 C09K 19/34 CA (STN) REGISTRY (STN)

Claims (4)

(57) [Claims] (1) General formula (Wherein R ¹ represents a linear or branched alkyl group having 7 to 15 carbon atoms, and R ² represents a linear or branched alkyl group having 9 to 16 carbon atoms) Alkyl pyrimidine compounds. 2. The compound according to claim 1, wherein at least one
A seed-containing smectic liquid crystal composition. (3) The compound according to the above (1), wherein at least one
A ferroelectric liquid crystal composition containing a seed. 4. The compound according to claim 1, wherein at least one
A liquid crystal device comprising a seed-containing ferroelectric liquid crystal composition.